Childhood depression.

My son Anthony, 10, is convinced that I love his sister, who is three, more than him.
He sometimes even says that we would be better off without him, which frightens me.
How can I build up his confidence again?

Your child is trying to make you react and tell you there is something wrong. His impression of how he fits into the family is not based on what you say, you could tell him 100 times how much you love him, without him believing you. How you behave is more important in his eyes, which he may have taken the wrong way at some stage.
As your son has spoken to you about how he feels, you can discuss it with him, ask him what makes him think this, what you did or said which upset him in the first place. It is a delicate situation, so try not to aggravate it as it could turn into depression. Sit him down, give him a cuddle and talk about it, don't sit on opposite sides of a table, as it will seem more like a confrontation. If this doesn't work, ask you GP to refer you to a child psychologist to stop depression before it starts. Try and involve him as much as possible and get him to take an interest in his sister.